Numerous aids are available to assist the golfer in improving his or her golf stroke. For example, it is useful to the golfer to be able to identify the location on the club face struck by the ball so that the golfer can modify his or her stance, grip or swing to improve the impact location to result in greater distance or avoid hooking or slicing shots. As with tennis racquets, golf club heads have a "sweet spot" which is the optimum location for striking the ball to provide maximum distance and accuracy.
One golfing aid which assists in determining the location of impact of the golf ball on the club head in a golfer's stroke is disclosed in U.S. Pat. No. 4,826,173 Brown. It provides a hook and loop fastener, one component of which covers the club face and the other component of which is made into a ring to form the "ball". When the club strikes the "ball" the "ball" sticks to the club face to indicate the impact location. This apparatus however does not reproduce the striking of an actual golf ball to allow the mimicking of an actual golf shot.
Another prior art device is disclosed in U.S. Pat. No. 4,898,389 Plutt. This device uses an array of electronic transducers attached to the club face to sense the impact of the ball and communicate electric signals to a processor which displays the point of impact electronically. Such a device is sufficiently expensive to produce and difficult to use to discourage widespread acceptance. A simpler device is disclosed in U.S. Pat. No. 5,033,746 Jones. this patent discloses a device for marking the point of impact of a golf ball on the face of a golf club. It comprises an outer translucent sheet of one colour which is connected to an underlying sheet of a contrasting colour. There is a layer of pressure sensitive adhesive between the two sheets such that the impact of a golf ball causes the two sheets to adhere and the colour of the underlying sheet to show through the translucent sheet in the area of impact. This device has been found to deteriorate after the impact and leave an imprecise impression of the impact location. Another similar device is disclosed in International Application no. PCT/GB89/01036, published 22 Mar. 1990 under WO 90/02586. In this device, two sheets form a pocket containing a high viscosity coloured liquid. The pocket is mounted on a club face by adhesive. The thickness of the viscous liquid and shape of the impact area indicates the point of impact of the ball on the club face and the impact angle.
Consequently there is a need for a golf club strike indicator which is inexpensive to produce, easy to apply and remove, can be re-used numerous times and provides an accurate impression of the impact location of the golf ball on the club face.